1. Field of the Invention
The present invention relates to a touch sensor that is provided with a plurality of electrode wires held inside a hollow tubular member and that provides a switching function by sensing the contact of the electrode wires caused by an external pressure, and a method for manufacturing the touch sensor.
2. Description of the Related Art
A touch sensor that serves to provide a switching function by sensing the contact of the electrode wires caused by an external pressure is used for a slide door etc. of automobiles (see e.g., JP-A-H10-281906 and JP-A-2000-57879).
The touch sensor disclosed in JP-A-H10-281906 is provided with a hollow tubular elastic insulator, and a plurality of the electrodes arranged separately from each other and spirally on an inner peripheral surface of the hollow tubular elastic body. The touch sensor is manufactured by arranging a plurality of the electrode wire along with an outer peripheral surface of the spacer that is formed same shape with the hollow portion, extruding rubber material to the outer periphery surface of the spacer and a plurality of the electrode wires and molding the elastic insulator, then pulling the spacer out.
The touch sensor (i.e., code switch) disclosed in JP-A-2000-57879 is provided with one pair of electrode wires (i.e., elastic conductors) are arranged opposite parallel to each other in an inner peripheral surface of the hollow tubular elastic insulator through the space. A shape of the elastic insulator in a cross section orthogonal to the central axis C of the elastic insulator is track shaped that both ends in width direction is formed arc-shaped. Each opposite surface of the pair of the electrode wires are linear in the central axis of the elastic insulator and inclined flat surface for the flat section of the outer surface of the elastic insulator. This touch sensor is manufactured such that whole shape is approximately elliptic-shaped add a spacer (i.e., solid member) whose shape is in same with the space between the one pair of the electrode wires and the one pair of the electrode wires, its outer peripheral surface is extrusion covered with the elastic insulator, then pulling the spacer out.